Expectation Values of Local Fields in an Integrable Theory after a Quantum Quench

TL;DR

This paper develops a generalized formula for calculating local field expectation values in integrable quantum theories after a quench, connecting relativistic and non-relativistic models like Sinh-Gordon and Lieb-Liniger.

Contribution

It introduces a generalized Leclair-Mussardo formula for integrable quantum field theories post-quench, linking relativistic and non-relativistic models through Bethe Ansatz techniques.

Findings

Derived a generalized formula for local field expectations after a quench.

Connected relativistic integrable models to non-relativistic limits like Lieb-Liniger.

Validated the approach by recovering known results in specific models.

Abstract

The expectation values of local fields of any interacting quantum theory after a quench process are key quantities for matching theoretical and experimental results. For quantum integrable field theories, we argue that they can be obtained by a generalization of the Leclair-Mussardo formula and a Bethe Ansatz result of Caux and Konik. Specializing to the Sinh-Gordon model and taking the non-relativistic limit, one can recover the results of Kormos et al. for the Lieb-Liniger model.